Area 6 - Environ Analysis, Monitoring, Health: Research Article

Background, Aim and Scope:
The xenoestrogens Bisphenol A, 4-tert-octylphenol and the technical isomer mixture of 4-nonylphenol (tech. 4-nonylphenol) belong to the group of chemicals which are called endocrine disrupters due to their property of causing hormonal dysfunctions in the endocrine system of organism at very low concentrations. Bisphenol A, 4-tert-octylphenol and the tech. 4-nonylphenol were determined in water samples collected from the influent and effluent of two German wastewater treatment plants (WWTP) during the long-time sampling period from February 2003 till August 2005 to estimate the occurrence and temporal variations in WWTPs.

Materials and Methods:
The compounds were extracted and concentrated from water by solid phase extraction using Bond Elut PPL cartridges and quantified by use of gas chromatography-mass spectrometry (GC-MS).

Results:
The influent concentrations were as follows: Bisphenol A < limit of detection of the method (
Discussion:
All analytes show highly fluctuating influent concentrations with very high peak concentrations at particular sampling times. The variation of effluent concentrations is by far lower than the variation of influent concentrations. For tech. 4-nonylphenol a significant temporal concentration variation has been detected with very high concentrations up to the µg/l-level in the time from February 2003 till July 2003 and clearly decreasing concentrations in the time from June 2004 till August 2005 which corresponds well with the implementing Di-rective 2003/53/EG (application of nonylphenol and nonylphenol ethoxylates in the European Union in different products is forbidden in concentrations equal or higher 0.1 % by mass) in 2005. Bisphenol A is present in the effluent samples either below the detection limit or with high concentrations up to the µg/l-level. For 4-tert-octylphenol no particular trend of concentration development has been observed.

Conclusions:
Combined SPE and GC-MS proved to be an efficient method to measure and identify organic compounds in environmental samples. With respect to the concentrations measured in the present study, Bisphenol A is the prominent compound in influent samples. Neither Bisphenol A nor 4-tert-octylphenol or tech. 4-nonylphenol show seasonal variations. However, there was a significant general trend of decreasing concentrations of tech. 4-nonylphenol in influent and effluent samples from both WWTPs which probably reflects the implementing Directive 2003/53/EG.

Recommendations and
Perspectives:
Further research is needed to investigate whether the observed decrease of tech. 4-nonylphenol concentrations in German WWTPs since June 2004 will continue further on. Bisphenol A is present in the effluent samples either